Recovery Boiler BLOX System Operation

SKU: C-734Duration: 23 Minutes

Pay-per-view (PPV) format perfect for individual users.

Get immediate access to this interactive eLearning course online. Must be used within 30 days, expires 48 hours after launch.

Language:  English

Great for trainers or groups who need unlimited online access to multiple courses. Available in two ways:

Recovery Series (Details)
Includes 8 courses for $499/year.

Pulping Library (Details)
Includes 72 courses for $1,499/year.

Ideal for corporate licensing and high volume users.

Get Convergence courses into your current LMS to track and report employee training. Or contact us to learn more about the advantages of licensing our courses with the Convergence LMS.

Course Details


Training Time: 23 minutes

Compatibility: Desktop, Tablet, Phone

Based on: Industry Standards and Best Practices

Languages: English

Some recovery boilers use waste heat from the combustion gases to evaporate water from incoming black liquor. This increases the efficiency in the amount of steam produced by the boiler. In direct contact evaporators, hot combustion gases directly contact black liquor. This concentrates the black liquor using waste heat, but it also adds unwanted emissions of malodorous sulfur gases to the flue gas. The black liquor oxidation (BLOX) system is designed to pre-treat the black liquor to minimize these emissions. This module covers direct contact evaporators and the theory and operation of the BLOX system.

Learning Objectives

At the end of this module, you will be able to:

  • Define the term TRS
  • Define the term BLOX
  • Explain where TRS comes from
  • Identify and describe a cascade direct contact evaporator
  • Identify and describe a cyclone direct contact evaporator
  • Describe where direct contact evaporators fit into the kraft recovery process
  • Explain the principle behind a black liquor oxidizer
  • Describe where black liquor oxidizers fit into the kraft recovery process

Key Questions

The following key questions are answered in this module:

What does BLOX stand for?
BLOX is an ancronyn for Black Liquor Oxidation System.

Why are BLOX systems used?
BLOX systems are used in recovery boilers which have direct contact evaporators to lower the total reduced sulfur emissions in the boiler flue gas stream.

What is the primary compound that BLOX systems are trying to eliminate?
BLOX systems are used to lower the emission of TRS compounds, primarily hydrogen sulfide (H2S), in flue gas coming from recovery boilers with direct contact evaporators.

What is a direct contact evaporator?
Direct contact evaporators increase the solids in black liquor going to a recovery boiler by first contacting it with the hot flue gas coming from the boiler.

What is the principle of operation of a BLOX system?
The BLOX system uses oxygen to oxidize TRS compounds into more stable sodium compounds which do not enter the flue gas stream in direct contact evaporators.

Sample Video Transcript

Below is a transcript of the video sample provided for this module:

Cascade evaporators are typically positioned between the boiler economizer, and the electrostatic precipitator. A cascade evaporator is a large vat that holds the black liquor, and is connected to the boiler by large duct work. A cascade evaporator is usually located near the economizer to minimize the duct work. A cascade evaporator contains one or more large drums made of horizontally aligned tubes attached on the ends to round metal plates that create a cylindrical drum. There are spaces between the tubes that allow gases to pass through. The drum sits in the vat of black liquor and slowly rotates, picking up the black liquor on the tube surfaces. The combustion gases flow through and around the tubes, heating and evaporating water from the black liquor.

Customer Q&A

I would like to have several employees take multiple courses. How can I set that up?

We're in the process of making bulk course and multiple user purchases easier. But for now, you can order multiple courses and contact us with details on who you'd like to assign courses to. We can set up each user's training plan and make sure everyone gets the eLearning assignments they need.

Can I get a free full-length preview of a course to see what this course covers?

While we do our best to offer details on course contents, we don't normally offer full-length previews. But please contact us with more details for a better understanding of what your organizaton needs and how we can help.

Do I get a certificate when I complete a course?

Yes. All of our courses allow you to print a completion certficate upon successfully passing the integrated test at the end of each eLearning course.

How do I log in to take a course that I have already paid for?

You'll receive an email with login details moments after you purchase your pay-per-view (PPV) course. Just click the login link and enter the user name and password provided.

Do you have courses in different languages?

Yes. While all of our courses are originally produced in English, we develop many courses in a growing number of languages, including Chinese, Dutch, German, Italian, Japanese, Korean, Polish, Portuguese, Russian, Spanish, Tamil, and Thai. Available languages are normally displayed in the Course Details section on each course page.
Added to Cart! Click here to view your cart.